Shear



Sept. 21, 1948. McGARY ETAL 2,449,561

SHEAR Filed Oct. 3, 1944 2 sheets-sheet 1 Sept. 21, 1948.

EL. MOGARY ETAL SHEAR 2 Shets-Sheet 2 Filed Oct. 5, 1944 Patented Sept. 21, 1948 SHEAR Francis L. McGary and Charles E. McGary,

Hardinsburg, Ky.

Application October 3, 1944, Serial No. 556,968

' 6 Claims. (01. 30-451 Our invention relates to a shear for sheet metal and the like, and it is an object of the same to provide :a shear that shall have a simple, direct and powerful action.

Another objectis to provide improved connections between a movable operating handle and the movable shear blade in a shear of the bench type, though capable of use in other shears. Referring now to the drawings, which are annexedhereto andmade a part of this application, andin which similar reference characters indicatesimilar parts: l l l Fig. lis a side elevation of one form of the invention, a l

Fig. 2, an. elevation as viewed from the opposite side; with parts omitted and being on a larger scale, ,5 r l Fig. 3, a view similar to Fig. 1, but'with parts omitted and being on a larger scale, showing the shear open;

Fig; 4,-a top plan of the shear,

Fig. 5, a section on limb- 5 of Fig. 1.

In the drawings, reference character I indicates the base of the first form of theshear, having a flat under face at H, adapted to rest on a bench or other support having a flat upper face. Preferably the base is formed with a forwardly-projecting lip II that is adaptedto he slipped under a suitable holding means on the bench,- e. g., a U-shaped loop of metal in the form of ahoop fastened to the top of the bench and shaped to receive the lip and to hold it so as to prevent tilting movement of the shear with relation to the bench when the shear is operated. Obviously other holding means may be used to engage with the lip, and preferably they will be such as to permit ready separation of the shear from its support. A handle 12 fixed to or integral with the base has its outer end shaped to rest on the table or bench or other support for the shear when the sameis positioned for use.

A cutting blade l3 of specially hardened steel or the like is fixed to the base Ill by means comprising screws l4, l4 and l5, 15. The screws l4, [4 are threaded to the base and serve to adjust the blade toward and from another blade hereinafter described, so as to compensate for wear and the like, while the screws I5, l5 are mounted in the base and pass through elongated slots IS in the blade, these slots being shown as countersunk and as receiving the heads of the screws l4, [4, which are thus enabled to clamp the blade in place while yet being out of the way of the work by being below the upper face of the blade.

. A blade i1 is pivoted to the base l0 bya pivot [8, the latter blade carrying a pin l9 that is slidably engaged in a slot at the forwardend of the upper handle 20 ofthe shear. The handle 20 is mounted on a pivot pin 2| of a toggle member comprising a pairof links 22, 22 at opposite sides of the shear, said links being pivoted at one end to the base 10 at 23 andibeing connected at their other endsto the pivot 2|. The other member of the toggle consists of a pairof links 24, 24, located at opposite sides of the shear laterally toward itscutting edge, as shown in Figs.

1. and 5 and at 21 in Fig. 3, so that in cutting sheet metal for instance the shear-may be turned readily to the right or left about an axis perpendicular to the work; Thus variousshapes may easily be made, the shear turning 'withequal facility to either right or left, whereas with ordi-'- nary shears it is almost impossible to veer to the right. particularly to any considerable extent, and is even difficult to turn to the left. Usually we prefer toconstruct the blade ll so that its cutting edge lies in a gentle uniform curve, as shown in Fig. 3, though the blade l3 will usually have a straight cutting edge.

By shaping the blades so that they are narrow in a vertical sense adjacent their cutting edges, by inclining their under faces generally upward toward the righthand side of the shear (looking forward), and preferably inclining their upper faces in a like manner, the thin portions adjacent their cutting edges will turn the newly cut edges of the sheet metal or other work laterally aside over the low adjacent face of the adjacent shear blade, and so make it easy to change from a straight line cut to any desired angle or curve.

A rearwardly and downwardly inclined laterally curved slope at 28 (Fig. 2) aids in guiding the sheet metal downwardly and away from the shear. The blade I! has a sort of duckbill appearance when viewed from the left, on account of the curved upper lines at opposite sides of the same and by reason of the laterally andforwardly down-sloping face at 33 (Figs. 1 and 3), all of which aids in facilitating turning of the shear and guiding the edges of the cut material away from the shear.

The shear is characterized by few and simple parts, and further by ready demountability of parts. Thus the several pivots 2|, 23 and 25 consist of readily removable pins that are held by U-shaped spring clips or cotters 28 engaging in annular grooves in the pins or in slots at opposite sides of saidpins. The pivot I8 is formed by a stud screwed into" the base and having a nut 29 and a washer 30 for holding the movable jaw in place on it. The blade l3 can be removed or re'-" placed for sharpening, etc., by merely backing off the adjusting screws 14 and taking out the holding screws l5.

In operation, the shear being open as in Fig, 2, the handle 20 is forced downward, thereby simultaneously forcing the joint of the toggle at 2| downward and straightening the toggle, and also causing the pivot [9 to ride to the right in the slot-of handle 20, whereby it approaches the joint of the toggle-and so increases the power of the leverto rock the blade toward closed position as the-xsaid blade approaches that position. The pivot of the blade [7 and handle 20 is provided with an anti-friction sleeve 3| to reduce wear and 'to'provide a readilyreplaceable part at this point of heavy wear.

'While the shear so 'fardescribed is shown as being ofthe bench typethe principles of the same may be embodied in whole or in part in shears of other varieties, e. g. in a small hand-held and hand-operated shear to be used for cutting sheet metal or other like materials.

" The novel linkage used in the shear of Figs. 1 to 5 is one that can be utilized in many other hand-operated tools and deviceawhether operated by moving one handle'or more and which can also be used in other relations for transmitting force or motion, as will be obvious. It will be obvious also to those skilled in the art that many changes may be made in the devices of our invention, all without departing from the spirit of the invention; and therefore we do not limit ourselves to what is shown in the drawings and described in the specification, but only as indicated in the appended claims.

Having thus fullydescribed our invention, what we claim is:

'1. In la-shear, a handle, a blade rigid with the handle, a blade pivotally connected to said handle and having arearward extension, a toggle having pivotaily connected links one of which is pivoted to said handle, the other one of said links being pivoted to a rearward extension of said secondnamed blade, and a handle pivotally mounted on the pivot between the links of the toggle, the lastnamed handle having a, pin-and-slot connection with said rearward extension of the second-named blade.

2. In a shear, a handle, a blade fixed thereon. another blade pivotally connected tosaiclhandle, a toggle connection between said handle and the upper portion of said blade, and a handle carried by said toggle and having pin and slot connection with the second-named shear blade.

3. A shear having a handle, a blade fixed thereto, a coacting blade pivoted to the first-named blade, a toggle connecting the first blade to a point above the pivot of the second blade, a handle carried on the toggle, and a pin and slot connection between the last-named handle and the second blade.

4. A manually operated tool comprising a'handle, a jaw vfixedthereto, a'second jaw pivoted to the first, a toggle connecting said handle and said 7 6. Power transmitting means comprising a lever, a second lever pivoted to the first, a toggle connecting said levers at one side of theiripivot, and a third lever carried by the toggle and hav ing a pin and slot connection to the second lever rearwardly of its connections to said toggle. FRANCIS L. McGARY. CHARLES E. McGARY.

REFERENCES CITED The following references are of record in the file of this patent:'

UNITED STATES PATENTS- Number Name Date 1,092 Heinisch "Feb. 27, 1839 127,708 Rhamy June 11, 1872 160,563 Billings Mar.'9, 1875 57 9,085 Wesselmann Mar. 5, 1897 2,264,840 Isaac Dec. 2, 19M 

